Rickets, Scurvy, Beriberi Cast Studies

Rickets

Case 1: Incomplete Mineralization

A 4-year-old child is characterized by bone deformities due to incomplete mineralization, resulting in soft and pliable bones. There is also a delay in teeth eruptions. The child is diagnosed to have rickets.

Question 1. How many types of rickets are there?
Answer:

1. Vitamin D deficient rickets in children.
2. Osteomalacia in adult.
3. Vitamin D-resistant rickets.
4. Renal rickets.
5. Hypophosphatemic rickets.

Read And Learn More: Biochemistry Clinical Case Studies With Answers

Question 2. State the cause of the disease.
Answer: Vitamin D deficiency.

Question 3. Which biochemical investigations need to be carried out?
Answer:

• Serum Vitamin D level decreases.
• Alkaline phosphatase level increases.

Question 4. How can the disease be treated?
Answer:

• Vitamin D is given orally or injectable.
• Increase sun exposure in the morning and evening by increasing outdoor activities.
• Increase consumption of fish liver oil, fish, and egg yolk.

Rickets Clinical Manifestations

1. Insufficient mineralization causes soft and pliable bones.
2. Bone deformities and weight-bearing bones get deformed.
3. Bow legs, knock-knees, bossing of frontal bones, pigeon chest, and beaded chest appearance due to prominent costochondral junction (rickety rosary).
4. Harrison’s sulcus– transverse depression passing outwards from costal cartilage to axilla.

Osteomalacia Clinical Manifestations

1. Bones are softened due to insufficient mineralization and increased osteoporosis.
2. Patients are more prone to fractures.
3. Decreased serum calcium and phosphate.
4. Alkaline phosphatase– bone isoenzyme will increase.

RDA– Children 400IU/day

Adult– 200IU/day.

Biochemical Role

1. Increases serum calcium level by acting on the kidney, intestine, and bone.
2. Causes bone mineralization, remodeling of bone, and increases bone mineral density

Case 2: Low Bone Density

A middle-aged woman reported a history of pain in the back and limbs. She also gave a history of pathological fracture. Her bone scan revealed low bone density.

Question 1. What is the diagnosis and probable cause?
Answer: Osteomalacia due to vitamin D deficiency.

Question 2. Which serum enzyme level will be affected?
Answer: Alkaline phosphatase– bone isoenzyme.

Question 3. Suggest the treatment and preventive measures.
Answer:

• Treatment– Vitamin D is given orally or injectable.
• Prevention– Increase sun exposure in the morning and evening by increasing outdoor activities.
• Increase consumption of fish liver oil, fish, and egg yolk.

 

Scurvy

Case 1: Bleeding Gums, Delayed Wound Healing

A 10-year-old child was brought to the hospital with complaints of bleeding gums, delayed wound healing, and red hemorrhagic spots all over the body.

• Diagnosis– Scurvy.
• Deficient vitamin– Vitamin C (Ascorbic acid). RDA– 60–75 mg.
• Sources– Indian gooseberry (amla), guava, orange (citrus fruits), etc.

Functions of Vitamin C

1. Mnemonic to remember dehydroascorbate.
2. Interconvertible into dehydroascorbate.
3. Hydroxylation reactions– conversion of proline and lysine into hydroxyproline and hydroxylysine, helps in collagen cross-linking and strengthening.
4. Antioxidant.
5. Steroid synthesis.
6. Cataract prevention.
7. Oxidation-Reduction reactions.
8. Spare Vitamin A and Vitamin E in antioxidant function.
9. Tyrosine and tryptophan metabolism.

Deficiency Manifestations

1. Swollen and bleeding gums.
2. Scorbutic rosary– the beaded appearance of the chest due to prominent costochondral junctions.
3. Ecchymosis or hemorrhagic spots due to capillary fragility (defective collagen synthesis).
4. Delayed wound healing.
5. Pseudo paralysis due to joint effusion in chronic cases.

 

Beriberi

Case 1: Numbness In The Legs

A 40-year-old male came to the hospital with complaints of muscle weakness, difficulty to rise from squatting position and numbness in the legs.

• On examination- deep tendon reflexes were diminished.
• Personal history- he is a chronic alcoholic and takes unpolished rice in his diet.
• Lab investigation- decreased RBC transketolase activity.
• Diagnosis– Dry beriberi.
• Deficient vitamin– Thiamine.
• Active form– TPP (Thiamine pyrophosphate).
• RDA– 1-1.5 mg/day.

Sources of thiamine– Cereals, pulses– mainly in the outer layer (bran), polishing of rice removes 80% of thiamine.

Important Functions of TPP

1. Energy generation.
2. Nerve impulse transmission.

Important Reactions

1. Pyruvate dehydrogenase complex.
2. Alpha keto glutarate dehydrogenase complex.
3. Transketolase.

Deficiency Manifestation

1. Dry beriberi– neurological involvement
2. Wet beriberi– cardiac involvement and effusions
3. Infantile beriberi.
4. Acute fulminant CVS involvement– Shoshin beriberi.
5. Wernicke’s-Korsakoff’s syndrome.

Wernicke’s-Korsakoff’s Syndrome

1. Typically seen in alcoholics.
2. Because alcohol decreases the absorption of thiamine from the intestine and also interferes with the conversion of thiamine to TPP.
3. GOA MP mnemonic to remember symptoms.
4. Global confusion.
5. Ophthalmoplegia.
6. Ataxia.
7. Memory loss.
8. Psychosis.

 

Case 2: Memory Loss And Unstable Gait

An alcoholic individual had symptoms of memory loss and unstable gait. His blood pyruvate level was increased.

Question 1. What is the probable diagnosis?
Answer: Wernicke’s-Korsakoff’s syndrome.

Question 2. What is the biochemical basis of the increase in pyruvate and the presence of neurological signs?
Answer:

• Because alcohol decreases the absorption of thiamine from the intestine and also interferes with the conversion of thiamine to TPP.
• Decreased activity of TPP leads to the decreased activity of PDH complex and accumulation of pyruvate.
• Pyruvate accumulation in the brain causes neurological symptoms.
• Nerve impulse transmission is also affected by TPP deficiency.

Question 3. Which test can confirm the diagnosis?
Answer: Lab investigation- decreased RBC transketolase activity.